This "battery anxiety" was reported to be highest when participants were in an unfamiliar place or out and about, such as travelling (72.6%), when alone (50.9%), on a night out (29.7%), or while shopping (21.3%).

About 43% of respondents said they felt frustrated and anxious when they were low on battery, and 42% said they felt vulnerable when they completely ran out. Others said having having low battery made them feel cut off, isolated, angry, and scared.

We might be too dependent on constant contact

Having our faithful smartphones by our side all the time means we can send a message to our friends, family, or partner when we see something funny on the internet, when we want to plan a meet-up, or when we're dealing with something more serious, like having anxiety about a situation at work. However, this accessability to our loved ones for support on issues may make it more difficult for us to face things alone when we need to.

Being able to message our friends constantly means our lives become more reliable, when actually a little bit of unpredictability is good for us. According to one study, published in the Journal of Anxiety Disorders, people with anxiety or depression don't cope well with uncertainty.

Reaching for the phone to text your friend, partner, or relative when something happens, before you've had the chance to really think it through yourself, can be problematic, because they reassure you. This makes you feel better in the short run, but all you've done is put your mind at ease. You haven't really had the time to analyse the situation properly.

Next time something happens that worries you, such as your boss requesting a meeting at work, try not to reach for the phone. Receiving instant soothing words from a friend could mean you're putting yourself at risk of getting even more worried next time you're faced with something anxiety-provoking.

Phones shouldn't be our only coping skill

According to Amy Morin, a psychotherapist and clinical social worker who appeared on TEDx with her talk The Secret of Becoming Mentally Strong, using a smartphone for emotional support from friends can be helpful, but if people become overly reliant on it then it could become their only coping skill.

"That's a problem because it makes people dependent upon their phones and [on] others to regulate their emotions for them," Morin told Business Insider. "You don't want to become overly reliant on any one coping skill. Instead, it's important to have a toolbox full of tools that you can use to cope with tough challenges and uncomfortable emotions."

As well as being an emotional crutch, there is increasing evidence that smartphone use can take a toll on our mental health in other ways. In one study of 496 students, published in the journal Computers in Human Behavior, smartphone use and texting was negatively related to good grades at school and positively related to anxiety.

"When people receive notifications or messages, they find it rewarding, and they become addicted to that positive feeling which can lead to compulsively checking their smartphones," said Morin.

"People are becoming addicted to their phones, the same way they might become addicted to gambling. Heavy smartphone users often experience a sharp spike in anxiety and withdrawal-like symptoms when they're away from their phones."

Morin says it's important to establish healthy limits with our phones, which means being willing to turn them off sometimes.

"Take a digital detox for a weekend, a week, or even a month," she said. "Taking a break from technology could be good for your mental health."